The present invention relates to a device for adjusting a beam system. Such devices are particularly used in radar systems in motor vehicles for supporting the driver, e.g. by detecting objects, determining distances, determining direction, and/or measuring speed.
To correctly adjust a radar system in a motor vehicle to the road, a device is known from German Patent No. 42 01 214 where the orientation of the entire radar system is changed with respect to the motor vehiclexe2x80x94in the manner of adjusting a vehicle headlight.
If, however, the emitted radar beam is to maintain a desired characteristic property (antenna lobe), a geometric alignment of the beam source and the focusing arrangement relatively to one another is performed. Different adjusting mechanisms are already known for this purpose. From German Patent No. 690 17 043, a radar system is known where the beam source and the antenna lens are each attached at the ends of two tubes that are arranged coaxially with respect to one another and whose axial distance can be changed. By axially displacing the tubes relatively to one another, along the geometric axis of symmetry of the antenna lens, the beam angle of the antenna lobe can be changed. German Patent No. 196 42 810 describes an adjusting device where the beam source can be moved in a plane perpendicular to the radiation axis, relative to the antenna lens. In this context, the beam source is located on a base plate, which can be displaced by two wedge-shaped sliders, which can be moved by a threaded rod. As a result, it is possible to manually adjust the beam source and the antenna lens in a desired principal beam direction. According to another variation described there, the beam source can be tilted in three directions with respect to the radiation axis. For this purpose, the beam source is arranged on the flat surface of a base in the shape of a spherical segment, the base being able to rotate via two threaded members, which are offset relatively to one another at right angles at the periphery of the base, and which each counteract an opposite spring element.
In the case of the indicated adjusting device, it is disadvantageous that it does not permit changing the position of the beam source in the direction of the radiation axis while simultaneously rotating the beam source with respect to the radiation axis, so that the radar beam cannot be simultaneously tilted and expanded. This limits the possibilities for using the radar system in a motor vehicle, e.g. for measuring distance.
The present invention is associated with a series of advantages. Thus, as a result of the base, which is fixed by at least three supporting elements, the beam source can be freely moved relative to the lens axis. In a targeted manner, the beam can be tilted and the focusing can be changed to expand the beam. The beam system can be electrically calibrated or adjusted. Thus, the radiation pattern, i.e., the local measuring range, can be changed while the beam system is in operation.